Field
The present disclosure relates generally to communication systems, and more particularly, to discontinuous reception (DRX) and semi-persistent scheduling (SPS) as applied to machine-type-communication (MTC).
Background
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). LTE is designed to support mobile broadband access through improved spectral efficiency, lowered costs, and improved services using OFDMA on the downlink, SC-FDMA on the uplink, and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
Discontinuous reception (DRX) is a technique that may be used in wireless communications to conserve the battery life of a user equipment (UE). To perform DRX, the UE and the network may negotiate wake-up window periods during which the UE powers on the receiver to allow data transfer with the network. Outside of the wake-up window periods, the UE may turn the receiver off and enter a low or zero power state to conserve battery life.
In enhanced machine type communication (eMTC), channels may be bundled in the time domain, using repetitions in multiple subframes. Current semi-persistent scheduling (SPS) and DRX for MTC or eMTC may not accommodate such repetitions.